Consumer packages for liquid or pumpable foods such as, for example, milk, stewed fruits, blancmanges or tomato puree are often manufactured from foldable packaging material, for example packaging laminates comprising layers of fibrous material, aluminium foil and thermoplastic, which are fed in web or sheet form into packaging machines which, by folding, sealing and form-processing, convert the material into filled, sealed packaging containers. Packaging containers for long shelf life use, so-called aseptic packages, may be produced in that both the packaging material and the product are sterilized prior to finishing of the packages. Modern packaging machines of the above-outlined type work at a very high production output rate and, as a result, the packaging machines are relatively large and best suited for large-scale industrial production.
In the packing of foods which are produced on a limited scale or for a limited period of time, for example seasonal produce such as tomato puree and olive oil, tradition calls for the employment of glass bottles, jars or tubes which are delivered ready-to-use and are filled in relatively rudimentary filling machines either directly at or close to the food producers. No aseptic filling systems of this type are available, and when it is desired to impart long shelf life to the packed product, known preserving methods such as autoclaving are employed. Machines for blowing aseptic plastic bottles on site at the food producer are also known in the art, but have proved to be difficult to operate in a satisfactory manner from the aseptic point of view. Previously sterilized plastic bottles or other packaging containers are, of course, also conceivable, but the transport of empty prefabricated packaging containers is a drain on resources because of the large unutilised volumes involved.
It will be apparent from the foregoing introduction that there is a need for producing specifically aseptic packaging containers of the single-use disposable type which are simple and efficient to transport and well-suited for local handling and filling on a small scale at individual food producers. The packaging container must be capable of being transported in a space-efficient manner and it is therefore also desirable to realise a method which makes it possible to expand a compressed or flat-laid packaging container in connection with the filling process. It is finally also desirable in the art that products which have been sterilized beforehand, for example by heat treatment, can be packed under aseptically reliable conditions in order to ensure that the finished package will have the desired long shelf life.